In general, an air purifier, a device for purifying indoor air contaminated by dust, germs, and the like, through dust collection, sterilization, deodorization, and the like, includes a plurality of filters.
In order to increase efficiency of an air purifier and lengthen a lifespan thereof, filters are required to be periodically managed and replaced. In a related art air purifier, a time to replace a filter is determined depending on an operating time. That is, an operating time is measured, and when an accumulated operating time reaches a preset time, a time to replace a filter notification is displayed to allow a user to replace the filter. Thus, in the related art air purifier, since a filter is replaced depending upon an operating time although a time to replace the filter is varied according to an environment in which the air purifier is installed, it is difficult to replace a filter in a timely manner.